use std::io::{Read,Write};
use std::net::TcpListener;
fn main(){
    let listener  = TcpListener::bind("127.0.0.1:3000").unwrap();

    for stream in listener.incoming(){
        let mut stream = stream.unwrap();
        println!("have a connect");

        let mut buffer = [0;1024];

        stream.read(&mut buffer).unwrap();
        stream.write(&mut buffer).unwrap();
    }
}